Microlithographic projection exposure apparatuses are used for the production of microstructured components such as for example integrated circuits or LCDs. Such a projection exposure apparatus has an illumination system and a projection objective. In the microlithography process the image of a mask (=reticle) illuminated via the illumination system is projected via the projection objective on to a substrate (for example a silicon wafer) which is coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection objective to transfer the mask structure on to the light-sensitive coating on the substrate.
During operation of a microlithographic projection exposure apparatus it is desirable to set defined illumination settings, that is to say intensity distributions in a pupil plane of the illumination system, in specifically targeted fashion. For that purpose, besides the use of diffractive optical elements (so-called DOEs), the use of mirror arrangements is also known, for example from WO 2005/026843 A2. Such mirror arrangements include a plurality of micromirrors adjustable independently of each other.
Various approaches are also known for setting polarization distributions in the pupil plane and/or in the reticle in the illumination system for optimising imaging contrast in specifically targeted fashion. Examples are disclosed in WO 2005/069081 A2, WO 2005/031467 A2, U.S. Pat. No. 6,191,880 B1, US 2007/0146676 A1, WO 2009/034109 A2, WO 2008/019936 A2, WO 2009/100862 A1, DE 10 2008 009 601 A1 and DE 10 2004 011 733 A1.